4 prong relay help

[Lockjaw]

Guys I hate relays. I got a 30 amp 4 prong one from advance the other day to wire up my fuel pump, but I cannot figure out how it works, and don't understand the schematic.

I will see if I can put a picture up here.


l (30)

l (85) l (86)

-
(87)

That is the alingment, if you move 85 back to the left some. For some reason in preview it looks fine, but not when saved. When I connect positive to 86 and positive into the fuel pump to 85 the relay clicks, and adding 12 volts to either 30 or 87 does nothing. I have moved the 12 volts and positive fuel pump all around, and tried adding 12 volts to different plug numbers with no results.

What am I missing? Do I need a ground too? Oh and the legend shows a rectangle with a solid line thru it from 85 to 86, 30 looks like a Y with the left side missing, and 87 looks like an L turned top to the right, in between the Y and the rectangle.

Somebody please hook me up.

Thanks :confused: :confused: :confused:

[RED ALERT]

Maybe this will help:
Terminal 30-12V constant(unswitched voltage). Wire directly to battery positive post.
Terminal 87-This is relay output(load).Wire directly to the fuel pump positive post.
Terminal 85 & 86 these are the control side of the relay.
Make one a constant ground and the other a switched voltage,key switch, toggle etc.
It does not matter which you choose to make power or ground with 85&86,you just need to make one or the other.


Bob

[Lockjaw]

Many many thanks. :D

[SportJ-US-1]

But be sure to put a fuse at the battery for the power feed to the relay for the pump (terminal 30 wire), 15 amps should be big enough. Unprotected wires and componets tend to do very nasty things if a short develops. Up to and including b;lowing up the battery or starting a fire.

[Rickracer]

On terminals 85 & 86, you can switch either the power or the ground to energize the relay, doesn't matter. :cool:

[Lockjaw]

Yeah I am a big believer in fuses, I had a noise filter for a stereo catch on fire once. I surely don't want a fire back around 3 batteries and 2 gas tanks. :eek: :eek: